Trying to understand Redis memory management

[MP]

Hi

I'm trying to understand how Redis memory management works. Lets say I
set the memory limit to 10MB. As I understand, when the memory limit
is reached, Redis will refuse "write" commands and allow only "read"
commands.

Questions:

1) Does this mean that the persistent file size will also be ~ 10 MB?

2) If yes for #1, if I now set the memory limit to 5 MB and start
Redis server....does it ignore the file store or just load 5MB worth
of data?

3) In one of the forums it was said that when memory limit is reached,
Redis will try to expire volatile keys.
a) Does it mean, it'll just remove it from memory (and not from
persistent file as well) ?
b) Will the next "get" to the same key return a value from
persistent file?
c) If there are no volatile keys...how does Redis decide which
keys to remove.

Thanks in advance.

MP